Located in
../applets/clock/org.gnome.panel.ClockApplet.panel-applet.in.in.h:4

20.

English:

%l:%M %p

Translators: This is a strftime format string.
* It is used to display the time in 12-hours format
* (eg, like in the US: 8:10 am). The %p expands to
* am/pm.
Translators: This is a strftime format string.
* It is used to display the time in 12-hours format (eg, like
* in the US: 8:10 am). The %p expands to am/pm.